insert into test values(1,'col1')insert into test values(2,'col2')insert into test values(3,'col3')insert into test values(4,'col4')

select * from test

update test set col1=col1+1

select * from test

You will see it will update the column without any problem...:)

Now the reason:

We know SQL server works in Auto Commit mode means what ever query we write on Query Window automatically got comitted. Now this will only happen by the time it will complete its execution. So Once execution will be done all rows will be succesfully updated by new values.

Please let me know if you are facing any problem. Please share your script as well if its there.